Thickening agent for aqueous systems, formulations containing same and uses thereof

ABSTRACT

The present invention relates to novel associative thickeners pertaining to the HEUR category (Hydrophobically-modified Ethoxylated URethane), to intermediate aqueous formulations containing such thickeners, and to the final compositions, for example paint, lacquer, varnish or paper coating slip compositions.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a Continuation of U.S. Ser. No. 15/747,014,filed Jan. 23, 2018, now allowed, which is a 371 of PCT/FR2016/052022,filed Aug. 3, 2016. The present application also claims priority toFrench application 1557551, filed Aug. 5, 2015.

The present invention relates to novel associative thickeners belongingto the category of the HEUR (Hydrophobically modified EthoxylatedURethanes). These products comprise an ethoxylated associative compoundcomprising a carbon-based chain end and at least one methyl and/or ethylbranching. The present invention also relates to intermediateformulations comprising such thickeners and to the use of thesecompounds as thickeners in final compositions, for example paintcompositions.

Paints consist of fillers and pigments and at least one organic polymerknown as binder. In addition to the fillers, the pigments and thebinder, a paint composition also comprises a solvent (which is water inthe case of aqueous-phase paints), additives for the rheology, additivesfor the stability (storage, formation of the film, UV) and otheradditives for obtaining special properties. The behaviour and theproperties of the paints depend on the nature of their constituents, inparticular of the binder, fillers and pigments and also rheologicaladditives. They generally comprise one or more thickener(s), the role ofwhich is to control the rheology of the compositions containing it/them,both at the stage of their manufacture and during their transportation,their storage or during their implementation. Given the diversity of thepractical constraints at each of these stages, it is advantageous forthe formulator to have available a range of thickeners having differentrheological behaviours when they are used in the final compositions. Inaddition, these thickeners can confer additional properties on thecompositions, for example on the paints, which contain them.

The following are distinguished among all the thickeners for paints:

-   -   natural cellulose-based thickeners, also known as cellulose        ethers, of HEC type or of HMHEC (Hydrophobically Modified HEC)        type,    -   acrylic thickeners of non-associative type, known as ASE (Alkali        Swellable Emulsions) and those of associative type, known as        HASE (Hydrophobically modified Alkali Swellable Emulsions) and    -   associative thickening polyurethanes of HEUR (Hydrophobically        modified Ethoxylated URethane) type.

The thickening polyurethanes or HEUR result from the condensationbetween a compound of poly(alkylene glycol) type, a polyisocyanate andan associative compound of alkyl, aryl or arylalkyl type consisting of ahydrophobic end group.

Coatex is the source of numerous research studies on paint thickeners.Furthermore, Coatex markets the products of the Coapur® range, forexample the Coapur® XS products, which are non-ionic thickeningpolyurethanes providing rheological profiles which vary between thenewtonian type (low viscosity at low shear gradient) and/or thepseudoplastic type (high viscosity at low shear gradient).

The document U.S. Pat. No. 5,594,087 describes polyurethanes used asthickening agents for aqueous paint formulations, the rheologicalprofile of which is balanced at low shear gradient and at high sheargradient.

The document US 2007 293625 describes the preparation of polyurethanethickening agents for aqueous compositions with an effect at a low sheargradient.

The inventors have developed a novel thickening polyurethane which makesit possible to very notably increase the viscosity at a high sheargradient and to thus confer, on the composition containing it, a gooddynamic behaviour, that is to say a high viscosity at a high sheargradient, while maintaining a very good pigmentary compatibility. Thisthickener can be classified in the category of the thickeners ofnewtonian or “ICI builder” type.

A thickener of “ICI builder” type can be defined as a product whichleads to an increase in the ICI viscosity when its dosage within thepaint composition is increased.

This novel thickener can, for example, be used alone in a paintcomposition where it is necessary to have a high viscosity at a highshear gradient (for example a satin or gloss paint comprising a highlatex content).

It can also be used in combination with a thickener of pseudoplastictype. Such a combination thus makes it possible to obtain a compositionhaving a good dynamic behaviour related to the presence of the newtonianthickener and a good static behaviour related to the presence of thethickener of pseudoplastic type.

Such a thickener can be formulated in the aqueous phase and, as a resultof its specific structure, it makes possible thickening of the finalcomposition without requiring specific equipment or high shear energy.

This novel thickener has, at the chain ends, polyethoxylated hydrophobicgroups of formula (I):

in which:

-   -   x and y represent, independently of one another, 0 or 1,    -   p, q, s and r are integers at least one of which is non zero,    -   5<p+x+q+2r+yr+rs<11 and    -   n represents an integer or a decimal number varying between 20        and 40.

The document WO 2011/104599 (Coatex) describes rheology-modifyingpolymers for aqueous systems, in particular paint formulations. Thethickeners described, of acrylic thickener type, can in particularcomprise ethyl acrylate (EA), methacrylic acid (MAA) and polymerizablemonomer units of formula:

R-(AO)m-(BO)n-R′

in which:

-   -   R designates a polymerizable unsaturated group, for example        methacrylate,    -   A and B designate alkyl groups which are different from one        another and which have from 2 to 4 carbon atoms, for example        ethylene oxide and propylene oxide,    -   m and n are integers of less than 150 at least one of which is        non zero and    -   R′ consists of at least one group of the following formula:

CH₃—(CH₂)_(p)—CH(—CH₃)—(CH₂)_(q)—

-   -   in which        -   p and q designate integers at least one of which is non zero            and        -   5<p+q<13.

Such acrylic polymers have a different rheological profile from that ofthe thickeners of the present invention. Namely, they come within thecategory of acrylic thickeners of pseudoplastic type (high viscosity atlow shear gradient).

The document CA 2,129,932 (Bayer), for its part, describes polyurethanesfor thickening aqueous systems, these polyurethanes consisting ofalcohol of formula R₂—O-A_(y)H in which R₂ represents an aliphaticalcohol with from 16 to 22 carbon atoms.

Definitions

In the description of the present invention, the term “HEUR” is anacronym for “Hydrophobically modified Ethoxylated URethane”.

In the description of the present invention, unless otherwise indicated,the percentages expressed represent percentages by weight and areexpressed with respect to the total weight of the reference element. Forexample, when it is indicated that a polymer comprises 10% of a monomeror of a reactant, it is understood that the polymer comprises 10% byweight of this monomer or reactant, with respect to the total weight ofthis polymer.

In the description of the present invention, the expression “at leastone” designates one or more compound(s) (for example one or morepolyethoxylated alcohol compound(s), one or more polyol(s), one or morepolyisocyanate(s)), such as a mixture of from 2 to 5 compounds.

“Alkyl” is understood to mean a linear or branched C_(x)H_(2x+1) group,where x varies from 1 to 30, preferably from 10 to 30, indeed even from12 to 28.

“Formulation” is understood to mean the thickening intermediate entitycomprising the polyurethane agent according to the invention formulatedin order to be easier to use in the final composition to be thickened.For example, the thickening agent according to the invention can beformulated in the presence of water and of surfactants in order to bemore easily flowable/pourable and easier to incorporate in thecomposition to be thickened at room temperature. The viscosity of theformulation before its incorporation in the final aqueous compositionis, for example, less than 10,000 mPa·s at 25° C. and at 100 revolutionsper minute.

“Composition” is understood to mean the final entity to be thickened orthe thickened final entity comprising the polyurethane agent accordingto the invention optionally formulated in the presence, for example, ofwater and of surface-active agents, and also all of its constituents,the list of which depends on the final application. For example, thefinal composition comprises inorganic pigments and binders, if it is apaint composition.

DETAILED DESCRIPTION OF THE INVENTION

The polyurethanes of the present invention are thickeners for aqueouscompositions, for example aqueous paint compositions. They make itpossible to obtain high viscosities at a high shear gradient and to thusconfer, on the compositions, a good dynamic behaviour. These thickeningpolyurethanes can be categorized in the category of thickeners ofnewtonian or “ICI builder” type.

Some paint compositions, for example satin or gloss paints, whichcomprise few pigments (in comparison with a matt paint, for example) anda lot of latex, must have the highest possible viscosity at a high sheargradient. This is known as Cone Plan viscosity or ICI viscosity, denotedμ_(I) (mPa·s). The thickening polyurethane of the present invention isentirely suited to aqueous compositions of this type.

The thickening polyurethane of the present invention can also be used incombination with a thickener of pseudoplastic type. Such a combinationthus makes it possible to obtain a composition having a good dynamicbehaviour related to the presence of the newtonian thickener and a goodstatic behaviour related to the presence of the thickener ofpseudoplastic type.

This novel thickener has, at the chain ends, hydrophobic groups ofbicycloheptenyl type which are optionally polyalkoxylated.

HEUR Thickener

An object of the present invention relates to a thickener belonging tothe category of the HEUR (Hydrophobically modified EthoxylatedURethanes). It concerns a non-ionic associative thickening polymer foraqueous compositions.

The thickening polyurethanes or HEUR of the present invention resultfrom the reaction between a reactant which confers the associativity andwhich consists of an end hydrophobic group, a compound of polyol (forexample poly(alkylene glycol)) type and a polyisocyanate. In the contextof the present invention, the terms “reaction”, “condensation” and“polycondensation” are used equivalently.

More specifically, it concerns a water-soluble thickening polyurethaneresulting from the condensation:

-   -   a) of at least one polyethoxylated alcohol of formula (I):

-   -   -   in which:            -   x and y represent, independently of one another, 0 or 1,            -   p, q, s and r are integers at least one of which is non                zero,            -   5<p+x+q+2r+yr+rs<11 and            -   n represents an integer or a decimal number varying                between 20 and 40,

    -   b) of at least one poly(alkylene glycol) and

    -   c) of at least one polyisocyanate.

It is these novel polyurethanes which make it possible, for example, tothicken a paint composition at a high shear gradient (measurement of theICI viscosity, for example).

The polyurethane according to the present invention comprises, asconstituent a), a compound of formula (I). Such a compound is known, inthe context of the present invention, as “ethoxylated associativecompound comprising a carbon-based chain end and at least one methyland/or ethyl branching”.

The compounds of formula (I) comprise:

-   -   a polyethoxylated chain, itself consisting of from 20 to 40        ethoxylated units, for example of from 25 to 35 units,    -   a carbon-based chain end comprising from 8 to 14 carbon atoms,        for example 12 carbon atoms and    -   at least one —CH₃ or —CH₂—CH₃ branching.

In the formula (I), the carbon-based chain comprises from 8 to 14 carbonatoms, for example 8, 9, 10, 11, 12, 13 or 14 carbon atoms.

This carbon-based chain can comprise a branching. In this case, r takesthe value of zero. It can also comprise several branches, that is to sayone or more r unit(s). The branchings can be of methyl (—CH₃) and/orethyl (—CH₂—CH₃) type.

For the purposes of information, it is specified that, in the formula“5<p+x+q+2r+yr+rs<11”:

-   -   “yr” means that the values y and r are multiplied together,    -   “rs” means that values y and r are multiplied together and    -   “2r” means that the value of r is doubled.

The water-soluble thickening polyurethane can result from thecondensation of one or more polyethoxylated alcohol(s) of formula (I).

According to one embodiment of the present invention, the polyurethaneconsists of several polyethoxylated alcohols of formula (I). Accordingto another embodiment, said polyurethane consists of just onepolyethoxylated alcohol of formula (I).

According to one embodiment of the present invention, thepolyethoxylated alcohol has a formula (II):

in which:

-   -   x represents 0 or 1,    -   p and q are integers at least one of which is non zero,    -   5<p+x+q<11 and    -   n represents an integer or a decimal number varying between 20        and 40.

According to this embodiment, the compounds of formula (II) comprise:

-   -   a polyethoxylated chain, itself consisting of from 20 to 40        ethoxylated units, for example of from 25 to 35 units,    -   a carbon-based chain end comprising from 8 to 14 carbon atoms,        for example 12 carbon atoms and    -   a single —CH₃ or —CH₂—CH₃ branching.

According to another embodiment of the present invention, thepolyethoxylated alcohol has the formula (III):

in which:

-   -   p and q are integers at least one of which is non zero,        -   p+q=9 and    -   n represents an integer or a decimal number varying between 20        and 40.

According to this embodiment, the compounds of formula (III) comprise:

-   -   a polyethoxylated chain, itself consisting of from 20 to 40        ethoxylated units, for example of from 25 to 35 units,    -   a carbon-based chain end comprising from 8 to 14 carbon atoms,        for example 12 carbon atoms and    -   a single —CH₃ branching (methyl branching).

Furthermore, the polyurethane comprises, as constituent b), apoly(alkylene glycol). “Poly(alkylene glycol)” is understood to mean apolymer of an alkylene glycol derived from an olefin oxide. Thepoly(alkylene glycol) chains of the constituent b) according to thepresent invention include a proportion of ethyleneoxy groups, aproportion of propyleneoxy groups and/or a portion of butyleneoxygroups. The poly(alkylene glycol) chains according to the presentinvention can, for example, comprise a dominant proportion ofethyleneoxy groups in combination with a secondary proportion ofpropyleneoxy groups. Specific examples of alkylene glycol polymerscomprise: poly(alkylene glycol)s with an average molecular weight of1,000 g/mol, 4,000 g/mol, 6,000 g/mol and 10,000 g/mol;polyethylene-polypropylene glycols with a percentage of ethylene oxideof between 20% and 80% by weight and a percentage of propylene oxide ofbetween 20% and 80% by weight.

According to one aspect of the present invention, the polyurethanesresult from the condensation in particular of a poly(alkylene glycol)which is poly(ethylene glycol). It can, for example, be a poly(ethyleneglycol), the molecular mass of which varies between 2,000 g/mol and20,000 g/mol, for example between 8,000 g/mol and 15,000 g/mol (limitsincluded). Mention may be made, by way of example, of poly(ethyleneglycol) (or PEG) with a molecular mass varying between 10,000 g/mol and12,000 g/mol (limits included).

Furthermore, the polyurethane comprises, as constituent c), at least onepolyisocyanate. “Polyisocyanate” is understood to mean a compound whichcomprises at least 2 isocyanate —N═C═O functional groups.

According to one aspect of the present invention, the polyurethanesresult from the condensation in particular of a polyisocyanate which ischosen in the group consisting of toluene diisocyanate, toluenediisocyanate dimers, toluene diisocyanate trimers, 1,4-butanediisocyanate, 1,6-hexane diisocyanate, isophorone diisocyanate,1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate,4,4′-diisocyanatodicyclohexylmethane,1-methyl-2,4-diisocyanatocyclohexane, diphenylmethylene diisocyanate(MDI), for example 2,2′-MDI, 2,4′-MDI, 4,4′-MDI or their mixtures,dibenzyl diisocyanate, a mixture of 1-methyl-2,4-diisocyanocyclohexaneand 1-methyl-2,6-diisocyanatocyclohexane, hexamethylene diisocyanatebiuret, hexamethylene diisocyanate biuret dimers, hexamethylenediisocyanate biuret trimers and a mixture of at least two of thesecompounds.

According to one aspect of the invention, said polyurethane results fromthe condensation of:

-   -   a) from 1% to 29% by weight of at least one compound of formula        (I), (II) and/or (III),    -   b) from 70% to 98% by weight of at least one poly(alkylene        glycol) and    -   c) from 1% to 29% by weight of at least one polyisocyanate, the        sum of these mass percentages being equal to 100%.

According to another aspect of the invention, said polyurethane resultsfrom the condensation of:

-   -   a) from 3% to 10% by weight of at least one compound of formula        (I), (II) and/or (III),    -   b) from 80% to 94% by weight of at least one poly(alkylene        glycol) and    -   c) from 3% to 10% by weight of at least one polyisocyanate, the        sum of these mass percentages being equal to 100%.

According to one embodiment, the present invention relates to awater-soluble thickening polyurethane resulting exclusively from thecondensation of the following 3 constituents:

-   -   a) a polyethoxylated alcohol of formula (I):

-   -   in which:        -   x and y represent, independently of one another, 0 or 1,        -   p, q, s and r are integers at least one of which is non            zero,        -   5<p+x+q+2r+yr+rs<11 and        -   n represents an integer or a decimal number varying between            20 and 40,    -   b) a poly(alkylene glycol) and    -   c) a polyisocyanate.

The manufacture of the polyurethanes, which belong to the family of thethickeners of HEUR type, is known to the person skilled in the art, whomay refer to the teaching of the documents cited above in thetechnological background of the present invention.

Another object of the present invention also relates to a method for thepreparation of a polyurethane as described above, said method consistingof a condensation of its different constituents.

Formulation of the HEUR Thickener

The polyurethane according to the invention can be formulated orcoformulated with other constituents or components.

Thus, the present invention also relates to an aqueous formulationcomprising a polyurethane according to the invention, as describedabove.

This aqueous thickening formulation is intended to be incorporated in afinal composition, for example a paint, a paper coating colour or adetergent composition.

The polyurethane according to the invention can be coformulated in thepresence of water.

According to one embodiment, said aqueous formulation according to theinvention consists of:

-   -   1) from 5% to 50% by weight of at least one polyurethane        according to the invention, as described above, and    -   2) from 50% to 95% by weight of water, the sum of these mass        percentages being equal to 100%.

According to another embodiment, said aqueous formulation according tothe invention consists of:

-   -   1) from 5% to 25% by weight of at least one polyurethane        according to the invention, as described above, and    -   2) from 75% to 95% by weight of water, the sum of these mass        percentages being equal to 100%.

The polyurethane according to the invention can be coformulated inwater, in the presence of at least one surface-active agent. Thissurface-active agent makes it possible to formulate the thickener in theform of a less viscous aqueous liquid solution which can thus be moreeasily used by the formulator.

Thus, according to one embodiment of the present invention, said aqueousformulation comprises a polyurethane, as described above, and also waterand at least one surface-active agent.

“Surfactant” or “surface-active agent” is understood to mean a moleculeor a polymer consisting of at least a hydrophilic part and of at least ahydrophobic part.

The surface-active agent used in the context of the invention can bedifferent in nature; for example, it can be anionic or non-ionic.

This surfactant can be selected from the categories of ionic surfactants(in this case, preferably anionic surfactants) and/or non-ionicsurfactants and/or mixed surfactants (comprising, in the same molecule,a non-ionic and anionic structure). The preferred surfactant is composedof at least one surface-active agent selected in the category ofnon-ionic surface-active agents, optionally in the presence of ananionic surface-active agent.

Mention may be made, among the suitable anionic surface-active agents,of sodium, lithium, potassium, ammonium or magnesium salts derived fromalkyl ether sulphates with alkyl(s) varying from C₆ to C₁₂, in linear,iso, oxo, geminal, cyclic or aromatic configuration, or from C₁₂ alkylsulphates, from alkyl phosphate esters or from dialkyl sulfosuccinates.The anionic surface-active agents are preferably used with at least onenon-ionic surface-active agent.

Mention may be made, as examples of mixed surface-active agents, ofalkoxylated alkylphenol sulfonates. The non-ionic surface-active agentscan be used alone or in combination with an anionic surface-activeagent. Mention may be made, as preferred examples of suitable non-ionicsurface-active agents, of: ethoxylated (2 to 15 OE) C₄-C₁₈ alcohols,ethoxylated (2 to 40 OE) C₄-C₁₈ Guerbet alcohols, ethoxylated (2 to 40OE) single-branched C₁₀-C₁₈ alcohols, C₁₈ sorbitol esters, ethoxylated(2 to 20 OE units) sorbitol esters, ethoxylated (less than 15 OE) C₄-C₁₈acids, ethoxylated (30 to 40 OE) castor oil, ethoxylated (7 to 60 OE)hydrogenated castor oil, esters such as glycerol palmitate, glycerolstearate, ethylene glycol stearate, diethylene glycol stearate,propylene glycol stearate, polyethylene glycol 200 stearate andethoxylated (2 to 15 OE) C₁₈ esters. The hydrophobic chains cancorrespond to linear, iso, oxo, cyclic or aromatic structures.

According to one embodiment, the formulation comprises at least onenon-ionic surface-active agent optionally combined with at least oneanionic surface-active agent, at a total content by weight ranging from0.1% to 40% by weight, for example from 5% to 20% by weight or from 10%to 17% by weight. In this case, the ratio by weight between the twosurface-active agents can, for example, vary between 25/75 and 75/25.According to one embodiment of the present invention, the polyurethaneof the present invention is formulated in the presence of more than twosurface-active agents, for example three or four surface-active agents.

According to one embodiment, said aqueous formulation according to theinvention consists of:

-   -   1) from 2% to 50% by weight of at least one polyurethane        according to the invention, as described above, preferably from        5% to 30% by weight,    -   2) from 0.1% to 40% by weight of at least one surface-active        agent, preferably from 5% to 30% by weight and    -   3) from 10% to 93% by weight of water, preferably from 40% to        85% by weight, the sum of these mass percentages being equal to        100%.

The polyurethane according to the invention can be formulated in awater-miscible solvent. The main reason for the addition of an organiccosolvent is to lower the viscosity of this polyurethane in the water,in order to facilitate the handling. The polyurethane is, for example,formulated with one or more polar solvent(s) belonging in particular tothe group consisting of water, methanol, ethanol, propanol, isopropanol,butanols, acetone, tetrahydrofuran or their mixtures.

Two specific examples of water-miscible organic solvents are:

-   -   diethylene glycol monobutyl ether (also known under the name of        Butyl Carbitol™) or ethylene or propylene glycol ether and    -   butylene glycol ether.

The viscosity of the polyurethane as it is, before it is incorporated ina paint composition, for example, is advantageously less than 10,000mPa·s at 25° C. and at 100 revolutions per minute, so that it is easierto pour from the storage container and more rapidly incorporated in thecomposition to be thickened at room temperature. The water-misciblesolvent chosen for such commercial compositions has, to date,exclusively been an organic solvent.

The polyurethane according to the invention can be coformulated inwater, in the presence of a coalescent agent. Equivalently to a solvent,the coalescent agent makes it possible to formulate the thickener in theform of a less viscous aqueous liquid solution which can thus be moreeasily used by the formulator.

According to one embodiment, said aqueous formulation according to theinvention consists of:

-   -   1) from 5% to 50% by weight of at least one polyurethane        according to the invention, as described above,    -   2) from 5% to 30% by weight of at least one solvent and/or        coalescent agent and    -   3) from 20% to 75% by weight of water, the sum of these mass        percentages being equal to 100%.

According to one aspect of the invention, the aqueous formulationfurther comprises at least one additive selected in the group consistingof a biocide, a solvent, an anti-foaming agent, a pH regulator, acoalescent agent, an encapsulating agent and their mixtures.

“Biocide” is understood to mean a chemical substance intended todestroy, repel or render inoffensive harmful organisms, to prevent theaction thereof or to combat them in any other way, by chemical orbiological action.

“Anti-foaming agent” is understood to mean a substance or a formulationintended to destroy air bubbles within a homogeneous or heterogeneousliquid medium (or at its surface) or to prevent their formation.

“pH regulator” or “pH-regulating agent” is understood to mean a chemicalcompound which makes it possible to adjust the pH to the expected value.For example, the pH-regulating agent can increase the pH; this is thecase with bases, such as NaOH. Alternatively, the pH-regulating agentcan decrease the pH; this is the case with acids. “Coalescent agent” isunderstood to mean an agent used in paints which makes it possible tolower the paint Minimum Film Formation Temperature (MFFT) to atemperature suited to the application conditions desired (for example anMFFT of 5° C. for an external application). Mention may be made, asexamples of coalescent agents according to the invention, of propyleneglycol, butyl glycol, 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate or2,2,4-trimethyl-1,3-pentanediol diisobutyrate,2,2,4-trimethyl-1,3-pentanediol monoisobutyrate, glycol etherderivatives of Dowanol® type.

“Encapsulating agent” is understood to mean an agent which creates ahydrophobic environment, for example a solvation cage. Mention may inparticular be made, as encapsulating agent, of cyclodextrin.

According to one embodiment, said aqueous formulation according to theinvention consists of:

-   -   1) from 2% to 50% by weight of at least one polyurethane        according to the invention, as described above, preferably from        2% to 30% by weight,    -   2) from 0.1% to 40% by weight of at least one surface-active        agent, preferably from 5% to 30% by weight,    -   3) from 10% to 93% by weight of water, preferably from 40% to        85% by weight and    -   4) from 0% to 5% by weight of at least one other additive chosen        in the group consisting of a biocide, a solvent, an anti-foaming        agent, a pH regulator, a coalescent agent, an encapsulating        agent and their mixtures, preferably from 0.5% to 4% by weight,        the sum of these mass percentages being equal to 100%.

Final Aqueous Composition and Uses of the Polyurethane

An object of the present invention is an aqueous composition comprisinga polyurethane according to the invention or an aqueous thickeningformulation according to the invention, said final aqueous compositionbeing selected in the group consisting of a paint, a putty, a thickcoating, a waterproof coating, a lacquer, a varnish, an ink, a slurry, apaper coating colour, a cosmetic formulation and a detergentformulation.

Said composition is thickened using a polyurethane or an aqueousthickening formulation according to the invention.

Furthermore, the present invention also relates to the use of apolyurethane according to the invention or of an aqueous formulationaccording to the invention for thickening an aqueous composition, saidaqueous composition being selected in the group consisting of a lacquer,a varnish, a paint, a putty, a thick coating, a waterproof coating, anink, a slurry, a paper coating colour, a cosmetic composition and adetergent composition. According to one embodiment, the aqueouscomposition to be thickened is of the following types: gloss paint,semi-gloss paint, satin paint or all other paints with a low PigmentVolume Concentration (PVC).

The “pigment volume concentration” is defined by the following formula:

PVC (%)=100×V _(f)/(V _(f) +V _(b))

with V_(f) which represents the volume of the mineral fillers and

-   -   V_(b) which represents the volume of binders in the paint        formulation.

According to another embodiment, the aqueous composition to be thickenedis of the following type: paint comprising a medium or high PigmentVolume Concentration (PVC), varying between egg-shell paint and mattpaint. In this case, the thickening polyurethane of the presentinvention can be combined with another thickener having a pseudoplasticprofile.

According to an embodiment of the present invention, said polyurethaneor said aqueous polyurethane formulation is used as a levelling agent ofsaid aqueous composition. The polyurethane according to the inventionmakes it possible, for example, to increase the levelling value of thepaint which contains it, that is to say the self-smoothing ability ofthe paint during the application. This value can, for example, bemeasured on a contrast chart Leneta, ASTM D4062 standard, “flow &levelling”.

According to one aspect of the present invention, the aqueouscomposition comprises from 0.02% to 5% by weight of active ingredient ofsaid thickener.

According to another aspect of the present invention, the aqueousformulation comprises from 0.05% to 2% by weight of active ingredient ofsaid thickener.

“Weight of active ingredient” is understood to mean the dry weight ofpolyurethane according to the invention, independently of thecoformulation ingredients.

According to yet another aspect of the present invention, the aqueouscomposition comprises at least one mineral filler selected in the groupconsisting of calcium carbonate, kaolin, talc and silicate and/or atleast one pigment selected in the group consisting of titanium dioxide,iron oxide and zinc.

According to one aspect of the invention, the aqueous composition is apaint and comprises at least one dispersing agent, at least one mineralpigment or filler, at least one binder, at least one biocide, at leastone anti-foaming agent and optionally one surface-active agent, asurface agent and/or a coalescent agent, a solvent.

The examples which follow make possible a better understanding of thepresent invention, without limiting the scope thereof.

EXAMPLES

The viscosity of the test formulations or of the paint compositions isdetermined at different rate gradients:

-   -   at a low rate gradient: the Brookfield viscosity (Bk), which is        measured using a RVT-type Brookfield viscometer, in the        unstirred flask, at a temperature of 25° C. and at two        rotational speeds of 10 and 100 revolutions per minute with the        appropriate spindle. Reading is carried out after rotating for        one minute. Two Brookfield viscosity measurements, respectively        denoted μ_(Bk10) and μ_(Bk100) (mPa·s), are thus obtained,    -   at a medium rate gradient, the Stormer viscosity, denoted μ_(S)        (Krebs units or Kμ) and    -   at a high rate gradient: the Cone Plan viscosity or ICI        viscosity, denoted μ_(I) (mPa·s).

Example 1

This example illustrates the use of a thickener according to theinvention in a solvent-free aqueous satin paint formulation, thecomposition of which is given in Table 1 below.

It illustrates the thickening power of a polyurethane according to theinvention (tests 1-3 and 2-3), using a compound of formula (III). At thesame time, this example also illustrates polyurethanes outside theinvention (tests 1-1 and 2-1) and a HASE acrylic thickener outside theinvention (tests 1-2 and 2-2).

Tests 1-1 and 2-1 (Outside the Invention)

Said polyurethane results from the condensation of, expressed aspercentage by weight with respect to the total weight of thepolyurethane:

-   -   18.6% by weight of an alcohol of formula CH₃—(CH₂)₁₁—(OE)₃₀-OH,    -   77.5% by weight of PEG 10000 and    -   3.9% by weight of isophorone diisocyanate (IPDI).

Tests 1-2 and 2-2 (Outside the Invention)

These tests use an HASE acrylic thickener consisting of, expressed aspercentage by weight with respect to the total weight of the compound:

-   -   35.1% by weight of methacrylic acid,    -   52.8% by weight of ethyl acrylate and    -   12.1% by weight of a monomer which is the methacrylate of        oxo-C12-(OE)₃₀, that is to say a methacrylate monomer comprising        30 ethylene oxide units and a hydrophobic chain end of        CH₃—(CH₂)_(p)—CH(—CH₃)—(CH₂)q type with p+q=9.

Such a thickener corresponds to a compound as described in the documentWO 2011/104599.

Tests 1-3 and 2-3 (According to the Invention)

Said polyurethane results from the condensation of, expressed aspercentage by weight with respect to the total weight of thepolyurethane:

-   -   21.9% by weight of a compound of formula (III):

CH₃—(CH₂)_(p)—CH(CH₃)—(CH₂)_(q)—(OE)_(n)-OH  (III)

in which:

-   -   p+q=9,    -   n is equal to 30,    -   74.5% by weight of PEG 10000 and    -   3.6% by weight of isophorone diisocyanate (IPDI).

The polyurethanes are formulated in water in the presence of asurface-active agent which is a C₈-C₁₀ fraction of an alkoxylated fattyalcohol (Simulsol® OX1008). The PU/surfactant/water ratios are 20/5/75.

All the results have been combined in Tables 2 and 3 below.

For each of the tests, the μ_(Bk10), μ_(I) (in mPa·s) and μ_(S) (inKrebs units measured with the standard module) viscosities weredetermined according to the methods described above at T=0 and at T=24 hat room temperature.

TABLE 1 Constituent of the paint (g) Weight (g) Water 99.45 Dispersant(Coadis ® BR3) 3.9 Biocide (Acticide ® MBS) 1.3 Anti-foaming agent 1.31(Airex ® 901W) NH₄OH (28%) 0.5 TiO₂ (RHD2) 122.2 CaCO₃ (Omyacoat ®8500G) 84.5 Binder (Acronal 290D) 270.6 Monopropylene glycol 6.5 Texanol6.5 Anti-foaming agent 0.65 (Tego ® 825) PU thickener Series 1: 28.6(according to the tests) Series 2: variable (see Table 3) Water q.s.pfor 650 g in total

TABLE 2 Test 1-1 Test 1-2 Test 1-3 OInv OInv INV Dose (% by weight/totalformula) 0.88 T = 0 μ_(Bk10) 2,135 66,000 1,590 μ_(Bk100) 1,160 16,680835 μ_(S) 86 >141 78 μ_(I) 1.6 2.9 1.6 T = 24 h μ_(Bk10) 2,320 74,7001,720 μ_(Bk100) 1,296 18,600 946 μ_(S) 89 >141 81 μ_(I) 1.6 2.95 1.6

TABLE 3 Test 2-1 Test 2-1 Test 2-2 Test 2-3 OInv Oinv Oinv INV Dose % byweight/total 1.44 1.24 0.506 1.44 formula T = 0 μ_(Bk10) 3,030 3,04024,200 2,190 μ_(Bk100) 1,706 1,678 6,240 1,230 μ_(S) 96 96 127 88 μ_(I)3.4 2.8 1.6 2.8 T = 24 h μ_(Bk10) 3,580 3,560 29,250 2,550 μ_(Bk100)2,090 2,060 7,495 1,448 μ_(S) 102 101 135 92 μ_(I) 3.4 2.8 1.6 2.8

OInv: Outside the Invention

INV: According to the INVention

The polyurethane according to the present invention (tests 1-3 and 2-3)has a rheological profile of newtonian type: low viscosity at low sheargradient.

By comparison of the results presented of tests 1-3 and 2-3 (accordingto the invention), a significantly improved thickening at a high rategradient (μ_(I)) is observed in the paint formulation, whereas theBrookfield and Stormer viscosities are changed more moderately; this ischaracteristic of a newtonian thickener, “ICI builder” type, which makespossible selective increase in the ICI viscosity as a function of thedose.

The polyurethane of the present invention thus offers a good compromisebetween newtonian behaviour (which makes it possible to obtain lowviscosities at a low shear gradient and at a medium shear gradient) and“ICI builder” characteristic, which makes possible a selective increasein the ICI viscosity as a function of the dose used. The formulator canthus adjust the dose of thickener as a function of the rheologicalbehaviour desired at a high shear gradient.

The polyurethane outside the invention of test 1-1 makes it possible toobtain a thickening at a high rate gradient (μ_(I)) which is identicalto that obtained with the polyurethane according to the invention oftest 1-3. Nevertheless, it is observed that the Brookfield and Stormerviscosities obtained with the polyurethane outside the invention of test1-1 are overall higher than those obtained with the polyurethaneaccording to the invention of test 1-3 at an identical dose (0.88% byweight, with respect to the total weight of the composition).

The polyurethane of tests 1-1 and 2-1 generates an ICI viscosity whichcan be modulated as a function of the dose added to the formula but itis coupled to excessively high viscosities at low and at medium rategradients. The profile of this polyurethane is not sufficientlynewtonian.

As regards test 2-1a, the polyurethane dose is adjusted in order toobtain an ICI viscosity identical to that of test 2-3 and thus to beable to compare the viscosities at low and medium rate gradients. It isobserved that the viscosities obtained at low and medium shear gradientsremain too high.

1. A water-soluble thickening polyurethane obtained by reacting amixture comprising: at least one polyethoxylated alcohol of formula(III):

wherein: p and q are integers at least one of which is non zero, p+q=8or 9 and n is an integer or a decimal number of 20 to 40, at least onepoly(alkylene glycol) having a molecular mass of from 2,000 g/mol to20,000 g/mol and at least one polyisocyanate.
 2. The water-solublethickening polyurethane according to claim 1, obtained by thecondensation of: from 1% to 29% by weight of the at least onepolyethoxylated alcohol of formula (III), from 70% to 98% by weight ofthe at least one poly(alkylene glycol) and from 1% to 29% by weight ofthe at least one polyisocyanate, wherein a sum of mass percentages ofa), b) and c) is equal to 100%.
 3. An aqueous formulation comprising:the water-soluble thickening polyurethane according to claim 1, andwater.
 4. The aqueous formulation according to claim 3, furthercomprising: a surface-active agent.
 5. The aqueous formulation accordingto claim 3, further comprising: at least one additive selected from thegroup consisting of a biocide, a solvent, an anti-foaming agent, a pHregulator, a coalescent agent, and an encapsulating agent.
 6. Theaqueous formulation according to claim 3, consisting of: from 2% to 50%by weight of the at least one water-soluble thickening polyurethane,from 0.1% to 40% by weight of at least one surface-active agent, from10% to 93% by weight of water and from 0% to 5% by weight of at leastone additive selected from the group consisting of a biocide, a solvent,an anti-foaming agent, a pH regulator, a coalescent agent, and anencapsulating agent, wherein a sum of mass percentages of 1), 2), 3) and4) is equal to 100%.
 7. A method for thickening an aqueous composition,the method comprising: contacting the aqueous composition with thewater-soluble thickening polyurethane of claim 1, wherein the aqueouscomposition is selected from the group consisting of a lacquer, avarnish, a paint, a putty, a thick coating, a waterproof coating, anink, a slurry, a paper coating color, a cosmetic composition, and adetergent composition.
 8. An aqueous composition, comprising: thewater-soluble thickening polyurethane of claim 1 as a levelling agent,wherein the aqueous composition is selected from the group consisting ofa lacquer, a varnish, a paint, a putty, a thick coating, a waterproofcoating, an ink, a slurry, a paper coating color, a cosmeticcomposition, and a detergent composition.
 9. A method for thickening anaqueous composition, the method comprising: contacting the aqueouscomposition with the aqueous formulation of claim 3, wherein the aqueouscomposition is selected from the group consisting of a lacquer, avarnish, a paint, a putty, a thick coating, a waterproof coating, anink, a slurry, a paper coating color, a cosmetic composition, and adetergent composition.
 10. An aqueous composition, comprising: theaqueous formulation of claim 3 as a levelling agent, wherein the aqueouscomposition is selected from the group consisting of a lacquer, avarnish, a paint, a putty, a thick coating, a waterproof coating, anink, a slurry, a paper coating color, a cosmetic composition, and adetergent composition.